Linked Life Data

18975073

Source:http://linkedlifedata.com/resource/pubmed/id/18975073

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2009-6-10
pubmed:abstractText
Family 18 chitinases hydrolyze chitin through a substrate-assisted catalytic mechanism and are to a variable extent able to catalyze transglycosylation reactions. Previously Aspergillus fumigatus AfChiB1 was found to be able to catalyze transglycosylation reactions. Structural analysis reveals that AfChiB1 consists of an eight-stranded beta/alpha-barrel. Like other members of the family 18 hydrolases, AfChiB1 has conserved substrate binding site and catalytic acid, while a suitable nucleophile is missing. In this study, Trp137, Asp246, and Met243, which are close to the glycosidic cleavage site, were mutated to glutamate individually. As a result, the W137E remained its hydrolytic activity and was completely devoid of transglycosyl activity, while the D246E reduced its chitinolytic activity and increased its transglycosyl activity. And the M243E showed a remarkable reduction of chitinolytic activity and complete loss of transglycosyl activity. These results suggested that the transglycosyl reaction catalyzed by the AfChiB1 is due to lacking of nucleophile.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1573-4986
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
525-34
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Mutation of Trp137 to glutamate completely removes transglycosyl activity associated with the Aspergillus fumigatus AfChiB1.
pubmed:affiliation
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't